I have locked certain cells of a worksheet and password protected the
sheet. When a user clicks on the cells i have locked i wish that a
mesage pops up telling him thath eis unauthorised to use those cells
or something equivalent - Right now the cursor merely moves back to
last used unlocked cell. can this ne done?

PS By default when i proetect a worksheet all cells are locked and
when i click on a locked cell a warning does pop up informing me to
unprotect worksheet etc but when i lock selected cells this warning
does not pop up and instead behaves as explained above